U.S. Pat. No. 5,976,453 to Nilsson et al. describes a device and process for expanding strand material into a wool-type product. Such texturized products are intended for use as acoustic and/or thermal insulation in automotive and industrial applications. The disclosed device is capable of expanding strand material into a wool-type product having a density of from about 30 grams/liter to about 69 grams/liter. Such low density wool-type products are desirable for use as sound absorbing material in engine exhaust mufflers, and as silencers for HVAC systems. Low density wool-type products may also be used in other thermal and acoustic insulation applications. The disclosed device is also capable of expanding strand material into a wool-type product having a density of from about 70 grams/liter to about 140 grams/liter. Such high density wool-type products are desirable for use as sound absorbing material in engine exhaust mufflers, and as silencers for HVAC systems. High density wool-type products may also be used in other thermal and acoustic insulation applications. The disclosed device represented an improvement over prior nozzles by requiring less compressed air, i.e., the flow rate of air going into the nozzle is less than that required by prior nozzles. As a result, fewer or lower capacity air compressors were required in a plant using the disclosed devices. Furthermore, it was possible to employ smaller tubing and regulators associated with the air compressors. Further still, a reduction of noise within the plant would likely result from the reduction in the quantity of compressed air used.
However, conventional texturizing devices, such as those disclosed in the '453 patent, suffer from drawbacks potentially affecting their efficiency and/or reliability.
For example, as shown in FIG. 1, a first texturizing device 10 of the '453 patent comprises an outer nozzle section 30 and an internal nozzle section 40. The outer nozzle section 30 has an entrance portion 32, an intermediate portion 34 and an exit portion 36. The exit portion 36 includes an intermediate nozzle segment 38 and an outer nozzle segment 39. The intermediate nozzle segment 38 is integral with the intermediate portion 34 of the outer nozzle section 30. The intermediate nozzle segment 38 is also integral with at least a portion of the outer nozzle segment 39. Consequently, damage to the outer nozzle segment 39 requires replacement of the entire outer nozzle section 30 to remedy the damage. Typically such damage will occur during manual operation of the device 10, for example, when a user drops the device 10 or inadvertently bumps the outer nozzle segment 39 against a hard surface.
Replacing the outer nozzle section 30 is a relatively costly proposition based on damage isolated to the outer nozzle segment 39. Furthermore, such an approach is often wasteful as the entire outer nozzle section 30 may be discarded, although the damage is isolated to a terminal region thereof (i.e., the outer nozzle segment 39). Further still, replacement of the outer nozzle section can require a relatively long period of time, during which the device 10 cannot be used. Thus, overall efficiency of the production process utilizing the device 10 is reduced.
As another example, as shown in FIGS. 2 and 3, a fourth texturizing device 400 of the '453 patent includes a strand material locking device 490 integral with a main body portion 442 of the device 400. The strand material locking device 490 comprises a cylinder portion 492, a piston 494 and a spring 495. The cylinder portion 492 includes a main body section 510 and a cylinder cap 520 which is threadedly secured to the main body section 510. The main body section 510 includes an inner cavity 512 and first and second bores 514 and 516. The piston 494 is located within the inner cavity 512 and is capable of reciprocating therein. The spring 495 is provided within the inner cavity 512 and biases the piston 494 upward toward the cylinder cap 520 (see FIG. 3).
The first bore 514 in the main body section 510 extends between and communicates with the inner cavity 512 and a passage 448a of a connector portion 448. In this embodiment, the strand material locking device 490 is axially displaced from the connector portion 448. The passage 448a is coupled to a gas stream source 70 including a hose 72 coupled to a compressor (not shown) and a fitting 74 provided at the end of the hose 74. Pressurized air is provided to the passage 448a by the source 70. The second bore 516 extends between and communicates with the inner cavity 512 and a first passage 446 through which the strand material 20 passes as it moves through the texturizing device 400. The passage 446 is shown including a first section 446a having a first diameter and a second section 446b having a second diameter which is less than the first diameter of the first section 446a. For example, the first diameter may be about 5 mm while the second diameter is about 4 mm. The first section 446a is provided with a larger diameter so as to allow joined or spliced strands to pass into and through the passage 446 without stopping.
The cylinder cap 520 includes a fluid inlet 522 which communicates with a pressurized fluid source 496. The pressurized fluid source 496 comprises an air compressor (not shown), a flow control valve (not shown), a hose 496a coupled to the compressor, and a fitting 496b provided at the end of the hose 496a. The fitting 496b is threadedly received in a portion of the fluid inlet 522. Pressurized air flows from the compressor through the hose 496a and the fitting 496b to the fluid inlet 522. From the inlet 522, the pressurized air passes into the inner cavity 512 causing the piston 494 to move downwardly against the spring 495 (see FIG. 2). As the piston 494 moves downwardly, a nose 494a of the piston 494 moves through the second bore 516 so as to engage the strand material 20. The nose 494a grips the strand material 20 and holds it stationary in the first passage 446. The fluid source 496 is caused to provide pressurized fluid to the inner cavity 512 just before the cutter is operated to cut the strand material 20. Once the strand material 20 has been severed, the fluid source 496 releases the pressurized air from the inner cavity 512, thereby allowing the spring 495 to return the piston 494 to its retracted position (see FIG. 3).
The nose 494a of the piston 494 has a first size and the second bore 516 has a second size which is larger than the first size. Hence, a gap G3 exists between the second bore 516 and the piston nose 494a when the nose 494a is in its strand material engaging position (see FIG. 2). The gap G3 provides a path for pressurized air entering the inner cavity 512 through the first bore 514 to exit the inner cavity 512. Thus, during a filling cycle, the pressurized air entering the inner cavity 512 through the first bore 514 and exiting through the gap G3 prevents strand material 20 or portions of strand material 20 from entering the inner cavity 512. This prevents the locking device 490 from becoming inoperable due to a buildup of strand material 20 in the inner cavity 512. Such a buildup of material 20 might prevent the piston nose 494a from properly engaging the strand material 20 just before or during a cutting operation.
The use of the first bore 514 to convey pressurized air into the inner cavity 512 to prevent buildup of strand material 20 in the inner cavity 512 is dependent on the flow of the pressurized air. Consequently, the device 400 is not protected from strand material 20 or other debris entering the inner cavity 512 when the pressurized air is not being delivered to the inner cavity (i.e., when the gas stream source 70 is off or depleted), such as when the device 400 is off, idle, or otherwise in an inoperative state. By way of example, the inner cavity 512 is not protected from strand material 20 or other debris when a user is carrying the device 400 from one location to another. As another example, the inner cavity 512 is not protected from strand material 20 or other debris when the gas supply source is disconnected from the device 400.
Furthermore, since the pressurized air from the gas stream source 70 is also used to advance or otherwise move the strand material 20 through the device 400 (e.g., through the passage 446), the diversion of a portion of the pressurized air through first bore 514 as described above means that a greater quantity of pressurized air is required than would be needed for only moving the strand material 20. As a result, costs attributable to the pressurized air may be higher.
Further still, since the pressurized air flowing through the first bore 514 and into the inner cavity 512 exits the inner cavity 512 through the gap G3, the pressurized air contacts the strand material 20 in the passage 446 (i.e., in the first passage 446a) at an angle substantially perpendicular to the passage 446. As a result, the pressurized air flowing through the gap G3 impacts the strand material 20 in a direction perpendicular to its direction of movement through the passage 446, such that the pressurized air may urge the strand material 20 against a side of the passage 446. Consequently, the pressurized air contacting the strand material 20 at this angle and/or the resulting contact with the side of the passage 446 may prematurely compromise the integrity of the strand material 20. Furthermore, it may be more difficult to advance the strand material 20 through the passage 446 as a result of this crosscurrent of pressurized air.
In view of the above, the general inventive concepts provide an improved device and method for producing a texturized strand material.